12 research outputs found
Evaporative cooling systems to improve internal comfort in industrial buildings
Several studies were carried out to determine how hot or cold environments can affect task performance and can influence productivity. Usually, HVAC plants are exactly designed in order to guarantee comfortable internal conditions inside built environments, but not all kind of buildings are equipped with a heating or cooling plant, like for example, some industrial buildings. These buildings are often characterized by high internal thermal loads. For those buildings the ability of different plant configurations to improve indoor thermal conditions was considered taking into account the influence of several parameters, like weather conditions, internal gains, thermal transmittance, ventilation air flow rate, etc. Simulation results are compared in terms of energy savings and thermal comfort. \ua9 2017 The Author(s)
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A âheart rateâ-based model (PHSHR) for predicting personal heat stress in dynamic working environments
The parameter of human body metabolic rates has been popularly used for the prediction of human heat stress in hot environments. However, most modules use the fixed and estimated metabolic heat production. The aim of this study is to develop the prediction of personal heat stress in dynamic working environments. Based on the framework of the predicted heat stress (PHS) model in ISO 7933, a heart-rate based PHSHR model has been developed using the time-based heart rate index, which is suitable for prediction in situations where metabolic rates are dynamic and there are inter-individual variations. The infinitesimal time unit Îti, has been introduced into the new PHSHR model and all the terms used in the PHS model related to metabolic rates are thus redefined as the function of real-time heart rates. The PHSHR has been validated under 8 experimental combined temperature-humidity conditions in a well-controlled climate chamber. The feature of the PHSHR model is being able to calculate dynamic changes in body metabolism with exposure time. It will be useful to the identification of potential risks of individual workers so to establish an occupational working environment health and safety protection mechanism by means of simultaneous monitoring of workersâ heart rates at the personal levels, using advanced sensor technology
Comparing the physiological and perceptual responses of construction workers (bar benders and bar fixers) in a hot environment
Comparisons between Shikoro-type helmet with no hood and typical fire protective helmets with hood in a hot and humid environment
A Method to Protect Mine Workers in Hot and Humid Environments
Background: Work comfort studies have been extensively conducted, especially in the underground and meteorological fields resulting in an avalanche of recommendations for their evaluation. Nevertheless, no known or universally accepted model for comprehensively assessing the thermal work condition of the underground mine environment is currently available. Current literature presents several methods and techniques, but none of these can expansively assess the underground mine environment since most methods consider only one or a few defined factors and neglect others. Some are specifically formulated for the built and meteorological climates, thus making them unsuitable to accurately assess the climatic conditions in underground development and production workings. Methods: This paper presents a series of sensitivity analyses to assess the impact of environmental parameters and metabolic rate on the thermal comfort for underground mining applications. An approach was developed in the form of a âcomfort modelâ which applied comfort parameters to extensively assess the climatic conditions in the deep, hot, and humid underground mines. Results: Simulation analysis predicted comfort limits in the form of required sweat rate and maximum skin wettedness. Tolerable worker exposure times to minimize thermal strain due to dehydration are predicted. Conclusion: The analysis determined the optimal air velocity for thermal comfort to be 1.5Â m/s. The results also identified humidity to contribute more to deviations from thermal comfort than other comfort parameters. It is expected that this new approach will significantly help in managing heat stress issues in underground mines and thus improve productivity, safety, and health. Keywords: maximum sweat rate, skin wettedness, thermal comfort models, tolerable worker exposure times, underground mine environmen
Comparison of human thermal responses between the urban forest area and the central building district in Seoul, Korea
Which Environmental Indicator Is Better Able to Predict the Effects of Heat Stress on Construction Workers?
UTCIâWhy another thermal index?
This article was published in the International Journal of Biometeorology [© Springer] and the definitive version is available at: http://dx.doi.org/10.1007/s00484-011-0513-7Existing procedures for the assessment of the
thermal environment in the fields of public weather services,
public health systems, precautionary planning, urban design,
tourism and recreation and climate impact research exhibit
significant shortcomings. This is most evident for simple
(mostly two-parameter) indices, when comparing them to
complete heat budget models developed since the 1960s.
ISB Commission 6 took up the idea of developing a Universal
Thermal Climate Index (UTCI) based on the most advanced
multi-node model of thermoregulation representing progress
in science within the last three to four decades, both in thermophysiological
and heat exchange theory. Creating the essential
research synergies for the development of UTCI required
pooling the resources of multidisciplinary experts in the fields
of thermal physiology, mathematical modelling, occupational
medicine, meteorological data handling (in particular radiation
modelling) and application development in a network. It
was possible to extend the expertise of ISB Commission 6
substantially by COST (a European programme promoting
Cooperation in Science and Technology) Action 730 so that
finally over 45 scientists from 23 countries (Australia,
Canada, Israel, several Europe countries, New Zealand, and
the United States) worked together. The work was performed
under the umbrella of theWMO Commission on Climatology
(CCl). After extensive evaluations, Fialaâs multi-node human
physiology and thermal comfort model (FPC) was adopted for
this study. The model was validated extensively, applying as
yet unused data from other research groups, and extended for
the purposes of the project. This model was coupled with a
state-of-the-art clothing model taking into consideration
behavioural adaptation of clothing insulation by the general
urban population in response to actual environmental temperature.
UTCI was then derived conceptually as an equivalent
temperature (ET). Thus, for any combination of air temperature,
wind, radiation, and humidity (stress), UTCI is defined as
the isothermal air temperature of the reference condition that
would elicit the same dynamic response (strain) of the physiological
model. As UTCI is based on contemporary science
its use will standardise applications in the major fields of
human biometeorology, thus making research results comparable
and physiologically relevant